Method of treating metallic containers to make them capable of holding high vacuums



Feb. 25- 1,527,875

; P. IRWIN METHOD TREATING METALLIC CONTAINERS TO vMAKE THEM CAPABLE OF HOLDING HIGH VACUUMS Filed April 24, 1923 E IE. .1. 3 7

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tfozmu State of ew. York, have invented new useful Improvements in Methods of Treat- Patented Feb. 24, 1925.

I unite-n stares; ee.

ex o iwm, N, Y.

, METHOD on TREATING- METeLnrecoN'rAINER-s TO M LD G GH; AC MS- KrE iTIi M; earners, or,

T 0 all whom it may concern.

Be it known that I, Parson lnwrm a citizen oi the United States, residing at {New York city, in thecounty of New York-ant} ant exists in the surface porcsof all metalsand which gradually escapes, impairing; the vacuum.

One oi 'the objects of the invention-isto provide means for the removalof this-oceluded air.

A further object of the invention resides in the contemporaneous "removal in vacuum-s, from a metallic vessel, ofysaid occl'uded ai l, and the retention of vacuumconditions within said vessel. v

The method is exemplified by-its application to the manufacture of containers thermally insulatedby vacuum although this is only one of-many ways in which the invention can be carried out.

In the drawings Figure 1 is a longitudinal view in section, largely diagrammatic of a vacuum chamber in which a container to be thermally insulated by vacuum is positioned for treatment.

Figure 2 is a sectional view taken along the line 2-2 of Figure 1.

Referring now in detail to the several figures, the numeral 1 represents a casing forming a chamber 2 which is in communication by means of the conduit 3 with vacuum producing means of any approved type. The casing 1 is provided with a r M movable end 4, fitting thereagainst in an air-tight manner and removable for the insertion of the object to be treated. The opposite end of the casing 1 is furnished with a diaphragm 5 which is normally maintained fiat but which, when released, is capable of bulging inwardly through atmospheric pressure. The diaphragm is held tured at 14 for against the end ofthelcasing 1 in any suit able manner, such" as for-instance, between the 1 annular fi-anges G-and l' -provided re -spectivcl-y at the end of said the baseof a -spider 9, the centralFportion of which is bored 'tor the receptionot" 'astud casingand at 10, having itsinncrend afiixed to the-dist phragm- In-the illustration the central portion of said diaphragm is thickened-- *to *provide adequate thickness for. engagement by" saidst-ud. A wingnut 11 screws'aipon said stud and abuts against the central-portion-=of the spider 9 to hold the" diaphragm 59in" a substantially-flat condition. Release of the}CllElPhIElgHidS accomplished "by unscrewing said wingnu t.

The containerto be treated consists preferably eta blank ofrelativelythinnietal which is doubled at 12, by anysuitable means, "to-term anannular chamber whichterminates in an open tubular extension 13 of small dimension and preferably' arranged substantially axially oi -said annular "chamber; RblQ BIlCl 4; of the casing 1 is suitablyaperthe passage "ofan electrode 15 'for'med at-its inner fend with a-mushroomshaped I head 16 {adapted to-engage withthe position, A second-electrode 17 extends through tin-aperture 18 in the side wall of the casing, said electrode being formed with a perforated head 19 adapted to fit around the tubular extension 13 of the container to be treated and to cooperate with the electrode 15 in holding the vacuum container in place. A bar 20 or other appropriate means is pro vided within the casing 1 to support the tubular extension 13 and to serve as an anvil against which the extension is mashed or compressed to close the passage there through when said extension is acted upon by the sealing means which consists of the roller 21 rotatably mounted upon astem 22, fixed to the diaphragm 5.

When it is desired to treat a metallic container, the end 4 of the casing 1 is removed, together with the electrode 15 and the corn tainer to be treated is placed within the casing 1, with its tubular extension 13 extending through the perforation in the head 19 of the electrode 17 The removable head 4: is then secured in place upon the casing, and

upon itself, as shown The removinner endsurface*offtl1e -conta i-ner and 5 'assist ln l'i'olding :thelatt r in the electrode 15 is pushed inwardly until it snugly engages the container, holding the latter against displacement. Air is evacuated from the casing 1 through the conduit 3 and a current is passed through the elec trodes 15 and 17 heating the walls of the container, opening the pores thereof and driving out, by expansion, the occluded air entrapped in said pores. It is immaterial to the invention whether the exhaustion of air from the casing 1 and the heating of the container take place simultaneously or in sequence, it being essential only that the proper degree of vacuum exists at the time the container attains the right temperature.

\Vhen the desired degree of vacuum has been reached the electric current is discontinued the wing nut 11 is unscrewed from i the stud 10 to permit the diaphragm .5 to be bulged inwardly by atmospheric pressure and to carry the roller 21 over the tubular extension 13 to mash the latter between said roller and the bar 20, thus sealing the annular space within the container against the entrance of air. Here again it is immaterial whether the current be turned off before or after the sealing operation. It has been found that metal of which the container is formed and from which the occluded air has been eliminated by my improved method possesses a greater degree of hardness and elasticity than the same metal, not so treated.

My invention therefore includes, not only the method of producing a container thermally insulated by vacuum, but also the method of treating any similar metallic article in order to temper the metal of which such article is formed and to render it capable of maintaining high vacuum conditions, the method contemplating the steps of establishing the vacuum and heating the of vacuum conditions during the heating 1,

period until the desired degree of vacuum is obtained.

2. The method of treating a metallic container to make it capable of maintaining high internal vacuum conditions after having been sealed in vacuums, which consists in establishing vacuum conditions within said container, heating said container, continuing the maintenance of vacuum conditions during the period of heating until the desired degree of vacuum is obtained, and sealing said container in vacuums.

3. The method of treating a metallic container to make it capable of maintaining high internal vacuum conditions after having been sealed in vacuums, which consists in establishing continuous vacuum in and around said container, and successively heating said container in vacuo to cause the escape of occluded air from the metal walls thereof and sealing said container in vacuums.

In testimony whereof I have hereunto set my hand.

PAYSON IRlVIN. 

